Just as there are certain articles of clothing every woman should have in her wardrobe, there are classic pieces of jewellery that add easy elegance o a woman’s office outfit, formal wear, and casual clothes.
When we make a conscious choice about what we wear, we're also choosing how we present ourselves to the world. We may also tend to dress in ways that reflect how we feel. What we wear might even cause us to adopt characteristics associated with those items.
The simplest way is to measure an existing necklace (including a chain necklace or necklace with a pendant) that suits you or the outfit you're planning to wear. A tape measure will work a treat.
If you don't have an existing necklace...